Cardiff Airport could be bought by the Welsh Government amid an effort to turn its fortunes around and make it a key part of the country's economic growth plans.

First Minister Carwyn Jones said his officials had entered an exclusive due diligence agreement with the airport's current owner, TBI, and may proceed towards a re-nationalisation subject to the satisfactory completion of financial, legal and "value for money" considerations.

Announcing the agreement, Mr Jones said: "Over the past 12 months, I have repeatedly emphasised the importance to Wales of a dynamic international gateway airport in Cardiff.

"During the course of the year we have developed a very constructive and positive relationship with TBI.

"Together we have been discussing how best to develop the airport to position it for the challenges ahead.

"I can today announce the Welsh Government has agreed with TBI to progress towards the purchase of Cardiff Airport.

"Such an arrangement would enable us to develop a more coherent approach to our national infrastructure planning, and integrate the airport into our wider economic development strategy."

Image Caption:Cardiff Airport is 12 miles to the west of the city

The airport has been struggling in recent years and is on course to record its weakest passenger numbers for 15 years in 2012.

There were 1.2 million people who used the airport in 2011 - far fewer than the airport's record total of just over two million in 2007.

A major setback was the loss of bmibaby from Cardiff as the airline had operated 11 routes.

The airport's decline was seized upon by Mr Jones earlier this year when he publicly criticised the airport's owners and urged them to properly invest in it or put it up for sale.

He said the plan would be for an independent operator to run it on a "commercial basis" on behalf of the government, adding that it would not receive subsidies and must "demonstrate a return to the taxpayer".

His immediate goal would be to return passenger growth but admitted the ultimate goal was to secure long-haul flights to Middle Eastern destinations such as Dubai, as well as a North Atlantic route.

"They would be very useful to Wales," he added, while refusing to be drawn on a price the Government would be willing to pay.

The announcement drew criticism from his political rivals.

Liberal Democrat Assembly Member Eluned Parrott expressed concerns about the practicality as well as the cost to the public of the change of ownership.

She said: "I feel the airport will simply become a money pit, sucking in public funds at a time of economic restraint which will deliver no obvious return."

Welsh Labour's biggest rival, the Conservatives, also voiced scepticism over the plan.

"The First Minister has taken every opportunity to run down Cardiff Airport's reputation and force it into a position of weakness and thereby making it vulnerable to Welsh Government takeover.

"It is the role of government to provide first-class public services and create the conditions for a prosperous and competitive economy - rather than pursuing an ideological dreamland where everything is owned and controlled by the state."

But leader of Welsh nationalist party Plaid Cymru Leanne Wood said she would welcome public ownership of the airport.

"Cardiff needs to see the development of our international airport so that it is run properly, that it offers a wide choice of destinations at affordable prices and is a good shop front for people visiting this country," she said.